Grady Memorial Hospital and Fresenius Medical Care have reached a basic agreement on providing dialysis services for 22 immigrants whose regular treatment ended last week.

Details of the deal were still being worked out, a Grady spokesman said late Wednesday afternoon. A Fresenius spokeswoman confirmed in an email that an agreement had been struck.

The Grady spokesman, Matt Gove, said that under the new deal, Grady will help cover the cost of dialysis for the patients, who up until two years ago were regularly treated at the hospital’s outpatient facility.

Gove said the contract will be for at least 12 months, and that patients will be able to start returning to Fresenius clinics in the area. The 22 patients had been left in limbo after an agreement for their treatment expired a week ago.

Fresenius issued a statement saying the company reached ‘’a long-term agreement in principle’’ with Grady that would begin immediately.

‘’We worked tirelessly to forge partnerships in the community with compassionate medical professionals affiliated with the excellent medical institutions in Greater Atlanta who care about patient care as much as we do,’’ said the statement from Fresenius spokeswoman Jane Kramer.

Under the expired contract, Grady had paid Fresenius $750,000 for a year’s care of the uninsured immigrants. The patients are not U.S. citizens, and most are not in the country legally.

Grady, Atlanta’s largest safety-net hospital, closed its outpatient dialysis clinic in 2009 after heavy financial losses.

When the agreement expired last week, a dozen of the immigrants went to a Fresenius clinic in Atlanta for dialysis treatment, only to be turned away. Many of them then showed up at Grady on Saturday.

Grady medical staff examined the patients as to whether they were in an “emergent’’ condition and required immediate treatment, Gove said earlier this week. One patient needed that care, he said. Some of the patients also returned to Grady this week.

Dorothy Leone-Glasser, president of Advocates for Responsible Care, which has been advocating for the patients, said Wednesday that she was waiting for the details of the agreement. “Fresenius does not want these patients to go without dialysis care,’’ she said.

Fresenius Medical Care and Grady had been in negotiations up till the Aug. 31 expiration of the previous contract.

Grady’s recent financial trouble was clearly a key factor in the impasse.

Gove, the Grady spokesman, had said the hospital has lost $20 million so far this year, while Fresenius had net income last year of about $1 billion.

Grady no longer provides outpatient dialysis care, Gove noted.

People need dialysis when they develop end-stage kidney failure — usually by the time they lose almost all kidney function.

Dialysis uses a man-made filter to remove wastes from the blood, restore a proper balance of electrolytes, and eliminate extra fluid from the body.

Typically, patients need regular dialysis three times a week.

Medicare covers routine dialysis, but illegal immigrants are not eligible for that federal insurance program, and neither are some newly arrived legal immigrants.

A year ago, Fresenius agreed to treat 25 of the 38 end-stage renal disease patients at Grady’s expense, and treat five others as charity care cases. Emory Healthcare agreed to serve three more immigrants as charity, and Colorado-based DaVita said it would serve the other five as charity.

One of the 25 Fresenius patients has received health insurance, one has left the country, and another has discontinued treatment, the company said.